Mexican Long-tongued Bat (Choeronycteris mexicana)
- Protection Status Notes
- The Mexican long-tongued bat is a former Category 2 candidate species. This species is considered Sensitive by the U.S. Forest Service, is considered to be Rare in Texas and Mexico, is proposed as a Species of Special Concern in California, and is included in Arizona Game and Fish Department's wildlife of Special Concern in Arizona. Fewer than 400 individuals have been observed in the United States since 1906.
- Like other phyllostomid (leaf-nosed) bats, Choeronycteris mexicana has a leaf-like projection at the tip of its nose. It can be distinguished from other phyllostomid bats occurring in the U.S. by the following combined suite of features: short ears, a long, narrow rostrum, and the presence of a tail.
- Life History
- This species is considered to be rare in Texas and Mexico. Fewer than 400 individuals have been observed in the United States since 1906.
Very little is known of the migratory patterns this species follows. Over the past few years, these bats have arrived in Arizona in May, where they spend the summer. Apparently only females come north to Arizona, usually arriving in May. The young are usually born in late June to early July. In October and November, they depart their maternity roosts for Mexico and Central America, where they remain active during the winter. New data suggest that some individuals may over-winter in warmer areas of Arizona. There are fall and/or winter records in southern California and Texas.
Mexican Long-tongued Bats roost predominantly in caves, mines, rock crevices, and abandoned buildings. They usually roost individually or in groups of 15 or fewer, but some colonies may reach 40-50 individuals. Mexican Long-tongued. During the spring and summer they do not cluster, preferring to roost 1-2 inches apart in the twilight near roost entrances. In the fall when temperatures drop below 70° F (21° C), they have been observed to cluster in groups of 5-6. They are very sensitive to intrusion and tend to fly out of the roost when disturbed.
C. mexicana forages primarily on nectar and pollen of night blooming flowers such as agaves and columnar cacti. It also may eat the fruit of columnar cacti, along with incidental insects found on the fruit or flowers. Hummingbird feeders may help sustain individuals that arrive in Arizona early in the year, or remain into winter when traditional food sources are not available. However, sugar water lacks essential nutrients required for long-term survival. There is also evidence that they will forage on ornamental vegetation, such as Mexican bird-of-paradise.
- This bat occurs in a variety of habitats, including thorn scrub, palo verde-saguaro desert, semidesert grassland, oak woodland and tropical deciduous forests. Although most frequently found in desert canyons, they have been observed in oak and ponderosa pine habitat (up to 6,200 feet).
- C. mexicana is found in the southwestern United States through Mexico to El Salvador and Honduras. In the United States, it occurs primarily in southern California (the San Diego area), southern Arizona, southwestern New Mexico, and the southern tip of Texas. It has also been collected in the Grand Canyon National Park, in northern Arizona, with a single record from Las Vegas, Nevada.
- Threats and Reasons for Decline
- Possible threats to this species include recreational caving, natural or intentional mine closures, renewed mining, mine reclamation, and loss of food resources. They are very sensitive to intrusion and tend to fly out of the roost when disturbed. Long term sustainability of food sources is extremely important for this species. Modification of these sources by development, prescribed fire, or grazing can cause direct loss of food plants.
- Ongoing Recovery
- Since only a few specimens have been recorded from Texas, management recommendations tailored to this species cannot be made.
- More information is needed to document distribution and understand seasonal movement patterns for this species throughout its range in the United States. Studies are needed to understand roosting and foraging requirements. Known roosts need to be monitored for population trends. Since only a few specimens have been recorded from Texas, effective conservation measures for this species cannot be made.
Additional details can be found in the online version of The Mammals of Texas for the Mexican Long-tongued Bat